Propeller pitch control system



Dec. 1, 1959 c. RUSSELL 2,915,034

PRQPELLER PITCH CONTROL SYSTEM Filed Feb. 26, 1952 2 Sheets-Sheet 1 FIG. 1

IN V EN TOR.

CHARLES RUSSELL By K Dec. 1, 1959 c. RUSSELL 2,915,034

PROPELLER PITCH CONTROL SYSTEM Filed Feb. 26. 1952 2 Sheets-Sheet 2 IN VEN TOR.

CHARLES RUSSELL WWW United States Patent PROPELLER PITCH CONTROL SYSTEM Charles Russell, West Hartford, Conn., assignor to Bendix Aviation Corporation, Teterboro, N.J., a corporation of Delaware Application February 26, 1952, Serial No. 273,395

Claims. (Cl. 11534) The present invention relates to a novel propellerpitc-h control system.

An object of the invention is to provide a novel system to control the pitch of the blade of the propeller of a marine craft or vessel selectively from the main control station and engine room of the vessel.

Another object of the invention is to provide a manual fall back control operable from the engine room for controlling the pitch of the blades of the propeller 0f the vessel, and means operable in the engine room for transferring the control of the propeller pitch to the manual control from an electrical control system operable from the bridge or main control station of the vessel.

Another object of the invention is to provide a novel bevel gear differential motion storage device and follow-up rack and gearing arrangement cooperating therewith for controlling the pitch of the propeller of the vessel.

Another object of the invention is to provide a novel propeller pitch control system, including motor means controlled from the bridge or main control station of the vessel for operating a motion storagedevice, manually operable means in the engine room of the vessel for operating the motion storage device, together with means for transferring from manual to motor control at will and operable from the engine room of the vessel.

Another object of the invention is to provide a novel system to control the amount of pitch of the blades of a controllable pitch propeller from either the bridge of a vessel or from the engine room of the vessel and in which there is provided a manual fall-back control operable from the engine room of the vessel in the event of failure of the main bridge control.

Another object of the invention is to provide a novel control system for varying the pitch of a propeller of a marine craft or vessel, and including a novel switch and clutch arrangement operable from the engine room of the vessel for transferring the control of the propeller from the bridge of the vessel to the engine room at the will of an operator stationed in the engine room.

The above and other objects and features of the invention will appear more fully hereinafter from a consideration of the following description taken in connection with the accompanying drawings wherein several embodiments of the invention are illustrated by way of example.

In the drawings:

Figure l is a sectional inboard profile view of a typical marine craft or vessel embodying the novel propeller pitch control system.

Figure 2 is a schematic diagram of the propeller pitch control system.

Figure 3 is a detailed drawing of the novel bevel gear diiferentiahmotion storage device and follow-up gearing arrangement of the control system of Figure 2.

Figure 4 is a plan view of the motion storage device 7 of Fig. 3.

Patented Dec. 1, 1959 Figure 5 is another view of the motion storage device of Figure 4 with the control arm in an adjusted position.

Referring now to the drawing of Figure 1, the subject control system is arranged to control the pitch of the blades of a controllable pitch and reversible propeller 2 of a marine craft or vessel indicated generally by the numeral 4. The pitch of the propeller 2 may be controlled either from a main control station or bridge 6 of the vessel by a control unit 8 electrically connected into the control system as hereinafter indicated; or manually from an engine room 10 of the vessel by a control unit 12. There is further provided in the engine room 10 a control lever 14 manually operable for shifting the control of the propeller pitch from the bridge 6 to the engine room 10 at the will of the operator, as explained hereinafter with reference to the schematic diagram of Figure 2.

The controllable pitch propeller 2 may be of conventional type controlled by a suitable rack (not shown) adjustably positioned by a rod 16, shown in Figure 2,. and extending coaxially in a shaft 18. The rack extends into the hub 20 of the propeller 2. The rack is arranged so as to operably engage with suitable pinion gears (not shown) and of conventional type, made a part of eachof the blades of the propeller 2 so that moving the rod 16 forward-or aft causes the rack to rotate the pinions whereby the pitch of the blades of the propeller 2 is changed. The propeller 2 is in turn driven by an engine 22 which may be of the diesel type through a shaft 24, reduction gearing 26 and the shaft 18 in which is arranged in coaxial relation the propeller pitch adjusting rod 16 of Figure 2.

Such a controllable pitch propeller eliminates the need for a reverse gear and permits the use of an optimum propeller for each condition of load. It improves maneuverability with certain types of diesel engines in that the engine need not be stopped and reversed, but may be continuously run while the pitch of the propeller 2 is altered or reversed to reverse the motion or alter the thrust of the vessel.

Referring now to the schematic drawing of Figure 2, the dotted lines indicate thecontrol units 8 and 12 from the structure of the servo unit. The bridge control unit 8 includes a variable coupling electrical transmitting device or synchro 28 of conventional type having an input connected by conductor 30 to a suitable source of alternating current and a rotor 32 operated through a gear train 34 by a hand lever 36. The synchro 28 has an output electrically connected through suitable electric cable 38, switch 40 of conventional type and electric cable 42 to a matching receiver synchro or electric motor means 44 of conventional type and also connected by conductors 46 to the alternating current source.

The switch 40 is of the normally open type and electrically connects the synchro 28 and 44 in operative relation upon adjustment of lever 14 into actuating relation to a control button 48 of the switch 40 so that control of the synchro 44 is from control unit 8. Simultaneously with such adjustment of lever 14, a clutch or mechanical coupling 50 of a conventional type is operated by the lever 14 pivoted on bearings 52. The coupling 50 includes cooperating elements 53 and 54. Element 53 is fastened to a shaft 55, while element 54 keyed to a shaft 56 and longitudinally movable thereon is arranged to be individually positioned by a lever 14 to connect and disconnect shaft 55 and shaft 56 of rotor 58 of the synchro 44.

For reasons to be given, when the clutch 50 is operated by lever 14 so as to drivingly connect shaft 55 to rotor .shaft 56, the electrical connection between the synchros 28 and 44 is broken by the lever 14 disengaging control button 48 so as to permit switch 40 under force of a biasing spring in the switch mechanism, not shown, to assume a normally open circuit position.

The rotor 58 of the receiving synchro 44 is operatively connected through shaft 56, gears 60 and 61, and a differential gearing unit 62 so as to drive a motion storage device indicated generally by the numeral 64 and which may be of the type shown in detail in Figures 4 and and described and claimed in the copending U.S. Patent application Serial No. 273,020, filed February 23, 1952, by Charles E. Gregory, now US. Patent No. 2,839,031, granted June 17, 1958, and assigned to Bendix Aviation Corporation.

As explained in the last-mentioned copending application the term motion storage device is used to denote a mechanism in which motion from an initiating source in excess of a predetermined initial value may be stored without imparting a corresponding movement to a servo device controlled through the mechanism until such stored movement is expanded by movement of a motor means controlled by the servo device and which movement of the motor means effects through suitable followup means a counter action on the mechanism which removes the stored motion.

The motion storage device 64 has a valve actuating rod 66 controlling a hydraulic servo valve 68 of conven tional type and which directs the flow of high pressure fluid or oil from an inlet line 70 to either of two outlet lines 72 or 74 and from the other of the lines 72 or 74 to a drain conduit 75 in a conventional manner.

The output lines 72 and 74 lead to a main power cylinder 76 in which is slidably mounted a piston 78 or hydraulic motor means. The piston 78 under the force of the high pressure fluid positions the propeller pitch control rod 16 aflixed thereto and extending through one end of the power cylinder 76. Another rod 80 affixed to the piston 78 extends through the opposite end of the cylinder 76 and has affixed thereto a connecting arm 82 at the top end of which is affixed a movable rack 84.

Engaging the rack 84 are gears 86 and 88. Gear 86 drives a gear 90 which in turn meshes with a gear 92 which, as shown in Figure 3, is provided with a hub 94 to which is fastened one end of a hollow shaft 96. The other end of the hollow shaft 96 is fastened to a hub 98 of a gear 100 of the differential gearing unit 62. Intermediate gears 102 and 104 of the differential gearing are rotatably mounted on stub shafts 106 and 108 respectively of a differential spider 110 afiixed to a shaft 112.

As best shown in Figure 3, the gear 61, of the schematic drawing of Figure 2, is formed integral with a gear 114 of the differential gearing unit 62. The gears 92, 100, 114 and 61 are freely rotatable on the shaft 112. Aflixed to one end of the shaft 112 is secured the motion storage device 64, shown in Figures 4 and 5, and described hereinafter.

The mechanism 80, 82, 84, 86, 90 and 92 provides a follow-up means which operatively connects-the hydraulic motor means 78 to the differential gearing means 62 and through the differential gearing means 62 and motion storage device 64 to the servo valve 68. The follow-up means is so arranged that upon motion of the hydraulic motor means 78 in one sense as upon an adjustment of the valve 68 from a neutral position, the follow-up means acts through the differential gearing 62 to first adjust the motion storage device 64 in a sense to expend such motion as may be stored in the motion storage device 64 and thereafter through the device 64 adjust the servo valve 68 in a sense to return the servo valve 64 to the neutral position. Thus-the hydraulicmotor-means'78 follows the adjusted position of the hand lever 36 due to the follow-up action of the mechanism 80, 82', -84, 86, 90 and 92.

Pinion gear-88, engaging rack 84, has secured thereto a shaft 115 to which there is affixed at opposite ends thereof piniongears 117 and 119. The pinion gear 117 neutral or zero pitch.

engages a second gear 121 which in turn rotates a rotor 123 of a transmitting synchro 125. The synchro 125 is of conventional type and is electrically connected at its input 127 to the source of alternating current and has an output connected in a conventional manner through cable 129 to a receiving synchro or electric motor means 131 also of conventional type connected to the source of AC. at 133 and having a rotor 135 geared at 137 to a pointer 139 cooperating with a suitable indicator scale 141. Thus adjustment of the rotor of the transmitting synchro 125 will cause a corresponding adjustment of the rotor of the receiving synchro 131 so as to position pointer 139 to indicate to the operator of the lever 36 at the bridge or main control station 6 of the vessel the adjusted pitch of the propeller 2.

The bevel gear 119 at the opposite end of the shaft 115 is mated with a similar gear to which is connected at one end of a flexible shaft 147. A similar bevel gear assembly 149 at the other end of the flexible shaft 147 is connected with a gear train 151 to position a suitable pointer 153 cooperating with a suitable indicator scale 155, so that adjustment of the rack 84 will cause a corresponding adjustment of the pointer 153 so as to indicate to the operator of control unit '12 in the engine room 10 the actual adjusted pitch of the propeller 2.

As heretofore described, the clutch or mechanical coupling 50 is disconnected when the synchros 28 and 44 are electrically connected through switch 40. When the coupling 50 is connected the electrical connections between the synchros 28 and 44 are disconnected by the switch 40. As shown in Figure 2, the simultaneous operation of the clutch 50 and switch 40 is effected through lever 14 pivoted at 52 and cooperating with the coupling element 54 and switch 40 so as to disconnect the coupling element 54 from element 53 and close switch 40 for control of the propeller pitch from the bridge 6 upon a clockwise adjustment of lever 14; and engage coupling element 54 with element 53 and open switch 40 for control of the propeller pitch from the engine room 10 upon a counterclockwise adjustment of lever 14.

in the latter adjusted position of the lever '14, manual adjustment of the motion storage device 64 may be effected by adjustment ofa control lever 156 in the engine room 10. The lever 156 is arranged so as to adjustably position through gearing 158, bevel gear assembly 160, flexible shaft 162, bevel gear assembly 164, shaft 55, coupling 50, shaft 56 and gearing 60 and 61, the differential gearing 62 and thereby the motion storage device 64 to in turn control the position of the servo valve 68 and thereby the propeller pitch control piston 78.

Operation oft/1e propeller pitch control system The operation of the control system of Figures 1 and 2 will be first described when the control is from the bridge 6 of the vessel 4. In that case, the lever 14 of Figure 2 is first adjusted in a clockwise direction so that the coupling 50 is disconnected and the synchros 28 and 44 are electrically connected through switch 40. For purposes of explanation, assume first that the vessel 4 is lying dead in the Water with the propeller 2 turning over at When propeller thrust is required and the magnitude and direction determined, the hand lever 36 is moved to a position indicative of the desired pitch.

Moving the control lever 36 will rotate the rotor 32 of the transmitter synchro 28 to induce an electrical signal in the receiver synchro 44 causing an eelctromagnetic force producing a torque in the rotor 58 of the receiver synchro or electric motor means 44 effecting a corresponding adjustment of the rotor 58 of the receiving synchro 44 which in turn rotates the gears 60-61 of Figures 2 and 3 and gear 114 of the differential gearing 62. Since gear 100 of the differential gearing 62 is locked by the rack 84 through gears 92,90 and 86, the rotation of 5. the gear 114 in turn rotates intermediate gears 102 and 104 and through stub shafts 106 and 108, the shaft 112 of the spider 110.

The shaft 112 extends through the hollow shaft 96 and rotates with the intermediate gears to rotate the motion storage device 64, as hereinafter described. The motion storage device 64 in turn actuates the control valve 68 to direct hydraulic pressure medium supplied through inlet line 70 to the proper outlet line, for example, line 74. This hydraulic pressure medium acts on the piston 78 in cylinder 76 to move the propeller pitch control rod 16whereby the blades of the propeller 2 are adjusted to the desired pitch.

Because of the connecting arm 82, as the rod 16 moves, rack 84 will also move. As the rack 84 moves, pinion gear 86 will be rotated to rotate gears 9092 and hollow shaft 96. The rotation of shaft 96 rotates gear 100' of the differential gear 62 which, because gears 114, 61 and 60 are held stationary by the torque exerted by the synchro 44 causes spider 110 to rotate in an opposite direction to that previously described. Rotation of the spider shaft 112 connected to the motion storage device 64 rotates that assembly to move back to a neutral position the rod 66 of the control valve 68.

The centering of the valve 68 stops the flow of pressure medium to the power cylinder 76 and motion of shaft 16 and rack 84 stops. The gearing is so determined that the new position of the rack 84 corresponds to the ordered pitch as set into the system by lever 36 in the bridge control station.

Simultaneously with the rotation of gear 86 by the rack 84, the gear 88 also in engagement with the rack 84 isrotated. As shown in Figure 2, this gear 88 is connected through gears 117 and 121 to position rotor 123 of a transmitter synchro 125. As the rotor of the synchro 125 is positioned, the electrical signal induced and transmitted to the receiver synchro 131 causes the rotor 135 of the synchro 131 to position a pointer 139 in the bridge control station cooperating with the indicator scale 141 so as to indicate the actual pitch of the propeller 2 so that the ordered pitch determined by the position of the lever 36 and actual pitch as indicated by pointer 139 will be brought into coincidence.

Also connected to gear 88 by shaft 115 are the pair of bevel gears 119 and 145 which drive through the flexible shaft 147 and the gearing 149 a pitch indicator pointer 153 in the engine room 10. The indicator pointers 139 and 153 at the bridge control and engine room, respectively, in normal operation always indicate the actual pitch of the blades of the propeller 2 regardless of whether the bridge control lever 36 or engine room control lever 156 is in operation.

When control is desired from the engine room, such as, for example, under testing conditions, or under emergency conditions where, for example, the bridge controller may have been blown away by enemy fire or under conditions of electrical failure of the synchros or electrical power supply, the'manual control of the pitch of the propeller blades 'may be effected by operation of the control lever 156 in the engine room upon adjustment first of the transfer control lever 14 in a counterclockwise direction, so as to connect elements 53 and 54 of the coupling 50 and cause the switch 40 to electrically open the connecting circuit between the synchros 28 and 44.

Any order of change of pitch of the blades of the propeller 2 may be set by the engine room control lever 156 which through bears 158 and 160, flexible shaft 162, gears 164, shaft 55, coupling 50, gearing 60 and 61 and differential gearing 62 rotates the motion storage device 64 in the same manner as previously described, where the gears 60 and 61 were rotated by synchro 44. The servo valve 68 controlled by the motion storage device 64 and the servo piston 78 operates as previously described. It should be noted, however, that while the bridge control indicator pointer 139 will in" normal. operation still indicate the actual propeller pitch (as does the engine room indicator pointer 153) the position of the bridge control synchro 28 will have no significance because of the action of switch 40 in opening the connection between the transmitter synchro 28 and the receiver synchro 44. However, should the transfer control lever 14 be once again returned to the bridge control position, disengaging the coupling 50 and closing switch 40, the receiver synchro 44, which was heretofore manually adjusted by the engine room control lever 156 through shaft 55 and 56, will, upon the closing of switch 40, adjust the gearing 60, 61 and 62 and motion storage device 64 so as to bring the pitch of the propeller 2 to that selected by the position of the bridge control lever 36.

As can now be readily seenfrom the foregoing explanation and reference to the schematic drawing of Figure 2, the control system provides for remote propeller pitch control from either of two stations, the bridge or the engine room of the vessel. While control is not effected simultaneously from both stations, indication of the actual pitch of the propeller 2 is provided at both stations irrespective of which station is the control station at the time.

Motion storage device of Figures '3, and 5 The motion storage device 64 is an arrangement of a ,boss or gear having a single notch or tooth 166 and mating pinion arm 167. There is further provided a piloting cam 169 and pin 17!) attached to the gear 165 and arm 167, respectively. As can be readily seen in Figure 4, the single tooth gear .165 is a part of a wheel 172. This wheel 172 has the single tooth gear or central boss 165 and a wide flanged portion or internal ring 174 to which is secured by a bolt 176 the piloting cam 169. The arm 167 is pivotally mounted on roller bearings 178 and there is formed in one end of the arm 167 a tooth 180. There is mounted on thearm 167, near the tooth 180, the pin and at the opposite end of the arm 167. there is provided a bracket 182 to which is connected the push rod .66 for actuating the servo valve 68.

' As shown in Figure 3, the wheel 172 is affixed to and rotated by the spider shaft 112, so that the arm 167 moves a small angular amount only regardless of the rotation of the wheel 172. The wheel 172 can effect movement of the arm 167 only while the tooth 180 and the notch or tooth cut out 166 in the boss are engaged. Figure 5 shows the limit of angular motion of the arm 167 as the wheel 172 has turned to disengage the single tooth 180 from the notch,166. The wheel 172 may now rotate approximately 360 before it is stopped without imparting any further movement to the arm 167.

However, as the wheel 172 is rotated back by the spider shaft 112 through action of the follow-up rack 84, the cam 169 acts against the pin 170 on the arm 167 so as to pilot the tooth element 180 into the cut-out or notch 166 and cause the arm 167 to return the servo valve 68 to a neutral position.

It will be seen then that the motion storage device 64 in effect provides a maximum opening of the servo valve 68 with a'fcw degrees of rotation of the control synchro 44 in response to adjustment of the signal transmitting synchro 28 positioned by the control lever 36 and permits the control synchro 44 to be further rotated without changing the valve position upon additional movement being imparted to lever 36 and the transmitting synchro 28. Further, because of the non-engagement of the tooth elements 166 and 180 in the latter adjusted position, as shown for example in Figure 5, continued rotation of the wheel 172 in the same direction or in a clockwise direction, as viewed in Figure 5, imparts no further movement to the servo valve 68 and such motion is in effect stored up by the continued clockwise rotation of the wheel 172 until the engagement of cam 169 with pin 170 at the extreme limit of clockwise movement of the wheel 172.v Such motion stored in the device of Figure is not lost, since upon movement of the servo motor 78 in response to the initial adjustment of the servo valve 68, theservo motor 78 operates through the rod 80, arm 82, rack 84,.pinion gear 86, to rotate gears 90-92, hollow shaft 96, and gear 100 of the difierential gear 62' which, .because gears 114, 61 and 60 are held by the torque exerted by the synchro 44 causes spider 110 and shaft 112 to move wheel 172 in a counter-clockwise follow-up direction to ultimately reset the tooth 180 in notch 166 upon the stored motion aforenoted being expended. Thus the concept of stored energy is evident in that the followup motion of the rack 84 moves only the wheel 172, until the cam 169 engages the pin 170 on the arm 167 to re-engage the tooth 180 in notch 166 and return, the arm 16.7 toxthe neutral position.

The subject matter of .the motion storage device of Figures; 3, 4 and 5 is described and claimed in the, copending US. patent application Serial No. 273,020, filed February 23, 1952, by Charles E. Gregory, now US. Patent. N'o.,2,839,031, granted June 17, 19,58, and assigned to Bendix, Aviation Corporation.

Although oneembodiment, of the invention has been illustrated and described, various changes; in the form and relative arrangements of the parts may be made to suit requirements.

What is claimed is:

1. In a system for controlling pitch of a propeller of a marine vessel having a main control station and an engineroom; the combination comprising hydraulic motor means. for varying the pitch of said propeller, a servo valve for controlling said hydraulic motor means, an electric motor, means operatively connecting said electric motor to said servo valve, manually operable electric control means for controllingsaid electric motor from the main control station, manually operable mechanical control means to position said servovalve and operative from the engine room, said last-mentioned control means including amechanical coupling means for drivingly connecting and disconnectingsaid mechanical control means and said servo valve, switch means for electrically connecting and disconnecting said electric control means and said-electric motor, and manually operable means in the engine room to simultaneously operate said switch means and coupling means so as toselectively effect the connection of one of said control means while 'efiecting the disconnection of the other of said control means.

2. In a system for controlling pitch of a propeller of a marine vessel having a main control station and an engine room;v the combination comprising hydraulis motor means. for varying the pitch of said propeller, a servo valve for' controlling said hydraulic motor means, an electric motor, difierential gearing means operatively connecting said electric motor to 'said servo. valve, follow-up means for positioning the servo valve, said follow-up meansoperatively connecting said hydraulic motor means through said differentialgearing means to said servo valve, and propeller pitch indicator meansat said main station and in said engine room operatively controlled by said follow-up means, manually operable electric control means for controlling said electric motor from the main control station, manually'operable mechanical control means. to position said servo valve and operative from the-engine room, said last-mentioned control means including a mechanical coupling means for drivingly con- .necting and disconnecting said mechanical control means and said servo valve, switch means for connecting and disconnecting said electric control means and said motor means, and manually operable means in the engine room to simultaneously operate said switch means and coupling; means so as to selectively effect the connection of one of saidcontrol means while effecting the disconnection of the other of said control means.

3. In a system for controlling pitch of a propeller of a marine vessel having a main control station and an engine room; the combination comprising means for varying the pitch of said propeller, an electric motor, means operatively connecting said electric motor to said pitch varying means, manually operable electric control means for controlling said electric motor from the main control station, manually operable mechanical control means to adjust said pitch varying means and operative from the engine room, first means for drivingly connecting and disconnecting said mechanical control means and said pitch varying means, second means operatively connecting and disconnecting said electric control means and saidelectric motor, and manually operable means in the engine room for operating said first and second means.

4. For use in a system for controlling pitch of a propeller of a. marine craft of the type including motor meansfor varying the pitch of said propeller, and control means for said motor means; the combination comprising an electric motor for positioning said control means, first manually operable means for positioning said control means, electric control means for operating said electric motor, means electrically connecting said electric control means to said electric motor, means for opening said electrical connecting means, second manually operable means for operating said last mentioned means, coupling means alternately operable for drivingly connecting and disconnecting said first manually operable means and said control means, and means operatively connecting said second manually operable means to said mechanical coupling.

5. For use in a system for controlling pitch of a propeller of the marine type including motor means for varying the pitch of said propeller and control means for said motor means; the combination comprising an electric motor, manually operable means for positioning said motor control means, said last-mentioned means including a motion storage device for operating said motor control means, a power transmission for driving said motion storage device and coupling means alternately operable for drivingly connecting and disconnecting said manually operable means to said power transmission, means drivingly connecting said electric motor to said power transmission, manually operable electrical control means for controlling the electric motor, switch means for disconnecting said electrical control means from said electric motor, and a single manually operable lever for operating said-coupling means and said switch means.

References Cited in the file of this patent UNITED STATES PATENTS 

